The X-Pump Block (XPB) mixing system combines a variable-speed mixing control, heat source circulator, constant-speed system circulator, and heat exchanger in one unit. This combination delivers complete system isolation between the heat generation side of the system and the heat delivery side, whether radiant tubing, glycol-based snowmelt, baseboard, etc. The XPB can be set to operate as an outdoor reset control, a set point control, or a delta T limiting control without the use of special piping, balancing valves, closely spaced tees, external controls, or complex wiring; four pipe connections are needed. According to the manufacturer, the XPB is ideal for contractors who may be installing a furnace-based air system and would like to provide radiant heat for the kitchen, bathroom, sunroom, or a radiant-ready basement package also. The XPB can be combined with an existing water heater to retrofit radiant into any home, the company says.
Taco Inc., 1160 Cranston St., Cranston, RI 02920; 401-942-8000; 401-942-2360 (fax); www.taco-hvac.com